Remember the big ol’ earthquake that rocked Chile on Feb. 27 and put Hawaii on a tsunami alert? According to the National Aeronautics and Space Administration (NASA), our days were shortened by the quake.
Jet Propulsion Laboratory researcher Richard Gross computed that the Earth’s rotation changed, shortening each Earth day by 1.26 microseconds. That’s 1.26 millionths of a second.
In addition, the Earth’s axis moved about three inches.
So far, I can understand it. Here’s where they lose me. According to NASA:
By comparison, Gross said the same model estimated the 2004 magnitude 9.1 Sumatran earthquake should have shortened the length of day by 6.8 microseconds and shifted Earth's axis by 2.32 milliarcseconds (about 7 centimeters, or 2.76 inches).
Gross said that even though the Chilean earthquake is much smaller than the Sumatran quake, it is predicted to have changed the position of the figure axis by a bit more for two reasons. First, unlike the 2004 Sumatran earthquake, which was located near the equator, the 2010 Chilean earthquake was located in Earth's mid-latitudes, which makes it more effective in shifting Earth's figure axis. Second, the fault responsible for the 2010 Chiliean earthquake dips into Earth at a slightly steeper angle than does the fault responsible for the 2004 Sumatran earthquake. This makes the Chile fault more effective in moving Earth's mass vertically and hence more effective in shifting Earth's figure axis.
Didja get all that? Good. Now explain it to me.
1 comment:
HUH?
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